Devibhagavatapurana 3.28.3

3.28.3

catvāro jajñire tasya putrā lokeṣu viśrutāḥ |
rāmalakṣmaṇaśatrughnā bharataśceti nāmataḥ ||

He had four celebrated sons Râma, Laksmana, Bharata and Satrughna. These four sons were equally learned and beautiful and they always did actions agreeable to the king. Of these, Râmachandra was the son of the Queen Kaus’alya, Bharata was the son of Kaikeyî, and the good looking Laksmana and Satrughna were the twin sons of Sumitrâ. While young, they learned the art of archery and began to play with bows and arrows in their hands.